US2283498A

US2283498A - Multiple plug connector

Info

Publication number: US2283498A
Application number: US357840A
Authority: US
Inventors: Glennon Edward Joseph
Original assignee: COMAR ELECTRIC CO
Current assignee: COMAR ELECTRIC CO
Priority date: 1940-09-23
Filing date: 1940-09-23
Publication date: 1942-05-19
Anticipated expiration: 1959-05-19

Description

E. J. GLENNON MULTIPLE PLUG CONNECTOR May 19, 1942.

Filed Sept. 23, 1940 Patented May 19, 1942 2.283.498 MULTIPLE PLUG cormnc'roa Edward Joseph Glennon, Chicago, 111., assignor to Comar Electric 00., Chicago, 111., a corporation of Illinois Application September 23, 1940, Serial No. 357,840

8 Claims.

I This invention relates to electrical plug-in connectors especially the variety adapted to have a plurality of electrical conductors or wires connected thereto for plug-in connection to other conductors connected with terminals in a receptacle or terminal strip.

An object of the invention is to provide an improved connector of this class which will be simple in construction, r ged, yet smooth and positive in operation and adapted to prevent errors in effecting the union of the complementary connecting elements. Y

A further and more particular object is the provision of a connecting plug consisting of complementary members one of which includes a plurality of plug connectors and the other of which includes a similar number of spring clip plug receptacles, together with means forming a part of the frame for one of the complementary members adapted to guide the other member into a predetermined assembled relationship therewith and prevent reversal of said other member in fitting the plug-in contacts into' the receptacle.

A further object is the provision of a multiple connector consisting of a terminal strip, having a plurality of spring clip connectors, and a plug strip having a plurality of connecting plugs adapted to fit into the clips when the two strips are brought together, one end of the plug strip being provided with a cable-tying formation and the opposite end of the terminal strip being provided with a guide member, engageable with the cable-tying formation to prevent bringing the complementary connector members or strips together in reverse relationship, the guide formation otherwise being adapted to bear against the end of the plug-in strip opposite the cable-tying formation to facilitate insertion of the connecting plugs into the spring clips or receptacles.

A still further objection relates to the provision of improved female or spring clip receptacles and means for mounting the same between two insulated strips constituting the principal part of the terminal strip, an additional object in this respect relating to the provision of oppositely punched spring fingers on the clips or plug receptacles, the fingers being curved concavely to bear in self-cleaning, scraping engagement with the connecting plugs.

Yet another object relating to the spring contact fingers relates to the provision of a curvature at certain end parts thereof for initial engagement with the connector plugs to effect an easy and quick insertion of the latter.

A further important object relates to the provision of certain guiding formations on the male or plug-in connectors and adapted to co-act with openings leading into the spring clip receptacles as well as with the spring finger formations themselves to effect a positive and firm connection.

A still further object is the provision of certain cut-away formations on the metal frame parts of the terminal strip adapted to prevent engagement with the contact plugs on the complementary strip when the latter is rocked while in position on the terminal strip whereby to prevent short circuiting.

A further object is the provision of a spring contact jack formed from a unitary metal strip bent back upon itself with opposite presser fingers connected to the strip at opposite ends of the jack (with respect to a plug inserted therein) to shorten the electrical path and lower the resistance of a circuit therethrough.

Other objects, advantages and novel aspects of the invention reside in certain details of construction as well as the cooperative relationship of thecomponent parts of the illustrative embodiment described hereinafter in view of the annexed drawing, in which:

Fig, 1 is a side elevation of the complementary conductor members with the. plug strip rocked out of normal position.

Fig. 2 is a fragmentary end perspective of the complementary conductors and the guiding means for preventing reverse connection.

Fig. 3 is a transverse section along lines 3-3 of Fig. 2 showing the spring fingers on the female or jack receptacle or connectors.

Fig. 4 is a horizontal section along lines 4-4 of Fig. 3 showing the self-cleaning scraper formations on the spring contact fingers, th'e vie being to an enlarged scale.

Fig. 5 is a horizontal section along lines 5-5 of Fig. 1 showing parts of the terminal conductor strip and elevation.

t1;ig. 6 is a bottom-plan view of the terminal s r p.

Fig. 7 is a fragmentary end perspective of the plug-in strip showing the cable-tie.

Fig. 8 is an enlarged perspective detail of a special testing plug and complementary guiding formations on the terminal strip.

In Fig. 1 the terminal strip is generally indicated by the reference character In while the complementary or plug-in strip is generally indicated at H.

As seen in Fig. 2 the terminal strip consists of upper and lower insulated strips l2 and I3 clamped together by peened over portion I vide an outer end portion'constituting a lug 2| which fits snugly into a corresponding slot 22 formed along edge of the lower insulated strip IS, the two strips having aligned openings I 5 and |3a above each jack or spring clip and the latter being provided with a portion 23 which is clamped between the upper and lower strips and then extends downwardly through the aligned opening Na and is bent back upon itself to provide a bight portion, which is turned upwardly through the opening |3a again with an end portion '25 turned over and clamped between the upper and lower insulated strips. There are as many jack or spring clip connectors. as desired, the same preferably being arranged in pairs on opposite sides of the .terminal strip assembly, that is to say on opposite sides of the reenforced cross-bar IS.

The plug-in connector strip consists of a single thickness or strip 28 (Figs. 2 and 3 particularly) having a plurality of punched openings 21 therein adapted for alignment with the openings l2a in the terminal strip, and there being a plurality of substantially rigid plug-in connector fingers 28 arranged on the strip 28 so that each extends through one of the openings 21 with the upper portion 28a bent over and riveted as at 28 to the strip 26, each of said bentover portions having an upwardly projecting lug part 38 provided with an eye portion for soldered connection with a conductor 8| as illustrated in Fig. 7.

Since a plurality of conductors 3| must be led into position adjacent corresponding connecting plugs 28-88 on the strip 26, the conductors are preferably made up into a cable generally indicated at Ma in Fig. 7 and the cable is led unto the plug-in connector strip 28 along the center thereof between the opposite rows of lugs 30 and the several individual conductors 3| branched of! at convenient intervals for connection with their respective lugs.

A special feature of the improved connector assembly resides in the provision of a cable-tie at one end of the plug-in strip, this tie being formed in the .arrangement shown by cutting opposite notches 32 near the outer end of strip 26 so as to form a cross-piece or T-head 38 in the nature of a tail, which is alsoof importance in cooperation with certain guide means hereinafter to be explained. Means such as the waxed cord 34 may be engaged in the notches 32 around cable 3ia to secure the latter firmly in position on plug-in connector strip.

In order to facilitate the plug-in of the member II in the terminal strip Hi, there is provided guide means in the form of an upward projection Me on the bracket or foot [8, this projection being adapted to abut the end part 28a (Fig. 2) of the plug-in strip when the latter is positioned properly above the terminal strip ready for insertion of the plugged portions 28 in the correspondingly aligned holes |2a of the terminal strip. By the simple act of placing the end 28a deliberately against the guide proiection "a, it will be assured that the plug-in connector strip is in the proper longitudinal position relative to the complementary strip or connectors, and the possibility of reversing the connec-' tion is wholly prevented because the T-head projection or tail 33 at the opposite end of the plugin connector strip would engage the end of the guide projection I81: and prevent seating the plug-in connecting strip on the terminal strip.

A further feature of the invention relates to the formation of the spring contact fingers 28a and 20b on the jack or spring clip connectors, it being apparent from Fig. 3 that these fingers are sprung or biased toward each other from 5 opposite juncture points 28c and 28d on opposite whereby opposite marginal edge portions 20;; are

provided on each finger for scraping engagement with the surface of the connector plugs 28, thus assuring good electrical contact. Moreover as will appear from examination of Fig. 5, the opposite disposition of the juncture portions 28c and 20d of the fingers on each spring clip causes the fingers to bear against the plug 28 at vertically spaced points as clearly seen in Fig. 5, which tends to rigidify or stabilize the seating of the plug in its corresponding jack.

Since it is frequently desirable to insert individual connector plugs in any of the jacks or receptacle openings for purposes of makingtest connections or the like and since such single plugs do not have the rigidifying reenforcements of a mounting strip such as the plug-in connector strip 28, they commonly wiggle while in position and work loose or at best provide a poor electrical connection. To overcome such objectionable characteristics, the terminal strip or jack connections are especially designed as to the formation of the holes or plug openings He in the upper terminal-strip l2, these openings l2a, as shown to enlarged scale in Fig. 8 being conveniently characterized as having a dumbell shape." In other words, the openings are keyed, being of rectangular form with opposite central projection l2b.

The special plug consists of a thin strip of metal bent back upon itself at its mid-portion 88 and having lug formations 31 aligned at its opposite ends with an intermediate curvature or bulge 38 adapted to rigidity the plug and also permit a degree of yieldability in the main plug portions 38 upon insertion and withdrawal from the jacks. Opposite longitudinal edge portions of the strip on opposite sides of the bight portion fitting closely a ainst the main portions 39 of the plugs betwe n the flanged portion 40 thereof for positive and firm mechanical and electrical engagement.

It frequently happens that the plug-in connector H will accidentally or deliberately be rocked in the manner illustrated in Fig. 1 and in prior devices of this kind opposite plugs would bear against the metal of the end leg or bracket [9 and cause a short circuiting. To avoid this the end leg or bracket 19 of the improved terminal strip has a special cut-away portion indicated at Na in Figs. 1 and 5, so that the lower end portion 28a of the plugs will always clear the bracket, the form and extent of such cut-away portions being calculated in a definite relation to the length of the plugs 28 and distance of the nearest jack or terminal strip opening from bracket H! to assure such clearance, the dimensions varying with changes in size and number of connections for each individual connector assembly.

It should also be observed from Fig. that flat plug 28 is engaged respectively by the oppositely attached fingers c and 20d so as to provide a shortened electrical path in the nature of a by-pass or shunt around the main bend or bight portion 20 of the jack. Such reduction of terminal resistance is important, especially for current values from about one-quarter ampere upwards.

The preferred embodiment of the invention set forth herein has been described in detail for purposes of illustration, it being understood that the objects of the invention may be accomplished by other forms and arrangements of the specific means set forth, so that the invention is not to be limited to any precise details of form, location, or function except as may be provided hereinafter in the appended claims.

I claim:

1. In a device of the class described means providing a terminal jack connector including a pair of insulated strips provided with registering openings, a spring clip jack associated with each pair of registering openings, each jack consisting of a thin metal strip bent back upon itself with opposite end portions clamped between said insulating strips, and further provided with a pair of mutually biased presser contact fingers one of which is attached to the jack adjacent the bend thereof, while the other is attached at its end remote from said bend to provide a shortened electrical path around said bend, said fingers being disposed beneath the corresponding pair of openings to bear against opposite sides of a connector plug.

2. The device of claim 1 further characterized in that said contact fingers of each pair are concaved transversely of their length to provide opposite longitudinal contact edges engageable with the sides of said plug to provide a positive electrical and mechanical contact therewith, said plug being flat for positive surface contact with said edges.

3. In a connector plug of the class described including an elongated plug member for insertion in a jack, the combination of a jack in the form of an elongated metal strip bent back in a direction upon itself to provide oppositely spaced side portions Joined by a bight portion, one of said side portions having a contact finger punched out therefrom with an end portion attached to said side portion at a point spaced away from said bight in the direction of length of said jack, the remaining said side portion having a contact finger punched therefrom with one end portion attached to said remaining side portion at a point adjacently near said bight in the direction of the length of said jack, whereby said plug when received in said jack will be engaged by said contact fingers on opposite sides thereof in a manner to provide an electrical shunt path leading around and in electrical parallel with said bight portion, for the purpose of lowering the electrical resistance of a circuit through said jack and plug.

4. In a connector plug, the combination, with a plug having oppositefiat surface portions, of a jack having opposite spring presser fingers disposed to bear against said fiat surface portion respectively, said fingers being concaved toward said surface portion to provide opposite contact edges bordering the concaved portion whereby eachfinger has opposite edge portions contacting the corresponding fiat surface portions of the plug to provide a scraping electrical contact.

5. In a connector, a jack type contact consisting of a piece of metal bent back upon itself to provide opposite arms, each of said arms having a presser finger punched therefrom so as to remain attached near one end thereof to the corresponding arm, the end of attachment of one said finger being opposite from that of the other, whereby to provide a shortened electrical path through said fingers in engagement with a plug connected in said jack.

6. In a connector, a receiving contact structure for aplug-in contact, said structure including a conductive strip having a U-shaped portion including opposite side arms joined by a connecting bight portion, one said arm having a pressure finger attached thereto at a point relatively near said bight portion to project in the general direction of length of the corresponding arm; and the other said arm having a similar presser finger distinguished by being' attached to its said arm at a point removed from said bight portion by .the distance of the length of said finger.

7. In a connector, in combination, a fiat, elongated, contact plug, and a jack therefor including opposite side arms between which said plug is adapted to fit, each said arm having a presser finger extending in the general direction of length of said plug, each said finger being attached at one of its ends to its respective arm, and the attachment of one finger being at an end thereof which is opposite from that of the other finger.

8. In a connector, 9. contact finger of approximately elongated form adapted to engage a complementary elongated contact having substantially fiat contact surface portions and to engage and disengage with said contact finger by movement in the direction of length of itself and the finger, said finger having opposite longitudinal edges turned generally toward each other out of the plane of the remaining body portions thereof to present scraping contact edges engageable with said flat contact surface portions of said complementary contact.

EDWARD J. GLENNON.